Fig. 9. Immunohistochemical localisation of phosphorylated HSP27 in the ventricle of isolated amphibian heart perfused with H₂O₂. Hearts were perfused (A) under normal conditions, with 30 µmol l^-1 H₂O₂ for 2 min in (B) the absence or (D) the presence of 1 µmol l^-1 SB203580 or (C) with 0.5 mol l^-1 sorbitol for 15 min. Cryosections were incubated with phosphospecific anti-HSP27 antibody (1:200 dilution) and processed as described in Materials and methods. Representative photographs from three independent experiments are shown. Scale bar, 20 µm.